Shunt surgery and lecanemab therapy in patients with idiopathic normal pressure hydrocephalus and alzheimer's disease: a report of two cases.

Idiopathic normal pressure hydrocephalus (iNPH) is a condition in the elderly commonly treated with ventriculoperitoneal (VP) or lumboperitoneal (LP) shunt surgery. iNPH frequently coexists with Alzheimer's disease (AD), for which anti-amyloid-β antibodies such as lecanemab have recently become available. Because lecanemab may cause hemorrhagic imaging abnormalities, the timing of shunt surgery in relation to antibody therapy raises concern regarding perioperative bleeding risk. Here, we report two patients with iNPH and AD treated with different sequences of shunt surgery and lecanemab. No hemorrhagic complications were observed, although conclusions regarding safety should be interpreted cautiously.